What do you do to make your puppy eat if it is not eating?

A trip to your Veterinarian complete with a small sample of the puppy's stool. A good check up is necessary at this time. Make sure you are feeding a good name brand of dry puppy food such as Innova or Natural Choice, etc. not some cheap puppy food. Only your Vet can tell if your puppy is ill due to other reasons or not.